Portable and convenient cable force measurement using smartphone

Cable force measurement is an essential step in bridge construction and structural health evaluation; it has developed rapidly in recent years and can be achieved using a wireless sensor network, which greatly reduces the monitoring cost and improves the efficiency of monitoring compared with traditional monitoring methods. However, expensive sensors, devices, transfer systems, and professionally trained technicians are needed in a wireless network system. Therefore, it is necessary to develop a portable and convenient method that requires less professional components. Smartphones with powerful operating systems are becoming popular; some have built-in high-performance sensors and a network that can transmit data. Based on these facts, a novel cable force measuring method using smartphone was proposed in this work. An iPhone-based cable force measurement software named Orion-Cloud Cell (Orion-CC) was developed and launched in the Apple App Store by our group. It has the advantages of being low cost, convenient, time saving, and easy-to-operate. First, a comparison test between an iPhone and a wireless monitoring method was conducted to verify the feasibility of a cable force measuring method using smartphones. Second, Orion-CC was applied to laboratory cable model tests. A comparison of the results from Orion-CC and MATLAB post-processing data proved the accuracy and operability of this method. Finally, this method was applied to the Dalian Xinghai Bay Cross-sea Bridge, which demonstrated its efficiency in an actual engineering application.